Re: fuel/trim gauge
1) Wiring, 2) wiring, 3) wiring. Both of those gauges need +12 volts when the key is on. They need a ground, and they need a "sender" feed from the fuel tank sender for the fuel gauge and the trim sender on the engine for the trim gauge. Missing any one of those causes a dead gauge. The fuel tank sender requires a ground at the tank and trim senders on the engine do go bad. Ground the "S" (send) terminal on the gauge. It should peg full (fuel gauge) or full up (trim gauge). If not, you have a bad gauge or wiring. If both quit at the same time I would be looking at the +12 volt and ground connections at the gauge.
